JP2020059846A - Polyamide resin composition and molding including the same - Google Patents

Abstract

To provide a polyamide resin composition which is excellent in elastic modulus retention before and after water absorption, and is also excellent in impact resistance, toughness and thin moldability.SOLUTION: A polyamide resin composition contains a polyamide 610 resin (A) having a viscosity number (VN) of 135 ml/g or less, an ethylene-α-olefin copolymer elastomer (B) and a plasticizer (C), and contains 10 pts.wt. or more and 35 pts.wt. or less of the (B) and 1 pt.wt. or more and 20 pts.wt. or less of the (C) with respect to 100 pts.wt. of the polyamide 610 resin (A).SELECTED DRAWING: None

Description

  The present invention relates to a polyamide 610 resin, a polyamide resin composition containing an ethylene-α-olefin copolymer elastomer, a plasticizer, and a molded article obtained by molding the same.

  Polyamide resin is widely used in automobile / vehicle-related parts, materials / construction material parts, sports equipment, electric / electronic parts, etc. because of its excellent mechanical properties, heat resistance, chemical resistance, and the like.

  Further, in recent years, miniaturization and higher precision of parts have been advanced, and resin molded products are required to have characteristics of being thin. Specifically, it is required to have excellent balance of thin-wall fluidity and high rigidity and impact resistance even for a thin-wall molded product. On the other hand, when a thin molded product is molded using a polyamide resin, the water absorption of the thin molded product is likely to change due to the influence of the external environment. Therefore, there is a demand for a material whose rigidity does not change when it is absolutely dry and when it absorbs water.

  In response to this demand, development using a polyamide 610 resin having low water absorption has been actively carried out.

  For example, by compatibilizing a polyamide 66 resin having excellent heat resistance and fatigue resistance with a low water absorbing aliphatic polyamide resin such as polyamide 610 resin having low water absorption and excellent calcium chloride resistance, strength and heat resistance can be improved. Also, a resin pulley having improved calcium chloride resistance has been proposed (see, for example, Patent Document 1). Further, by using a conductive polyamide composition containing polyamide 610 resin or the like, stainless steel fibers and / or carbon nanotubes, impact modifier plasticizer, and plasticizer, fuel penetration resistance, conductivity, zinc chloride resistance An excellent fuel supply device component for an automobile has been proposed (for example, see Patent Document 2). In addition, X. Y / Z or 6. Y2 / Z at least one polyamide A1 (where X is a residue of a C6-10 aliphatic diamine, Y is a residue of a C10-14 aliphatic dicarboxylic acid, Y2 is a residue of a C15-20 aliphatic dicarboxylic acid) , Z is a lactam residue, an α, ω-aminocarboxylic acid residue, and at least one unit selected from the units X1 and Y1 (wherein X1 is an aliphatic diamine residue and Y1 is an aliphatic diamine residue). It is proposed that by using (dicarboxylic acid residue), it can be used at a temperature 20 to 30 ° C. higher than the use temperature of polyamide 12 resin and can maintain excellent flexibility, impact strength, chemical resistance and extrusion moldability. (For example, see Patent Document 3).

  In addition, fluidity may be required depending on the shape of the molded product. In particular, when molding a thin-walled molded product, the molten resin is likely to be rapidly cooled to the inside by the mold, and therefore the mold cannot be filled with the resin unless the material has excellent fluidity. As a fluidity improving technique, by using a composition containing a crystalline aliphatic polyamide resin, an amorphous or hardly crystalline polyamide resin, a reactive soft component, a modified cross-section glass fiber, and a plate-like crystal inorganic filler, A technique has been proposed in which, in addition to having rigidity and toughness, low warpage, and a good design surface appearance, good fluidity and low burr properties, which are contradictory properties, are compatible (for example, see Patent Document 4).

JP, 2008-202693, A Japanese Patent Publication No. 2007-537928 JP2012-107244A JP, 2010-248406, A

  Thin-walled molded products such as nets, lattice-shaped molded products, sheets, buttons, and electronic device cover parts are required to be compositions having excellent fluidity in order to form product shapes. Further, under high humidity, the mechanical properties of the thin-walled molded product may be greatly reduced from the absolutely dry state. Therefore, there is a need for a polyamide resin composition in which deterioration of mechanical properties due to water absorption is suppressed.

  However, none of the above Patent Documents 1 to 3 evaluate the change in mechanical properties due to water absorption.

  In addition, the polyamide resin composition described in Patent Document 4 has a fluidity capable of forming a thin wall of less than 1.3 mm by using a low-viscosity resin as a resin, but is evaluated for its characteristics during absolute drying and during water absorption. I haven't.

  In view of the above circumstances, it is an object of the present invention to provide a polyamide resin composition which is excellent in elastic modulus retention before and after water absorption and is also excellent in impact resistance, toughness and thin-wall moldability.

That is, the present invention is as follows.
(1) A polyamide resin composition containing a polyamide 610 resin (A) having a viscosity number (VN) of 135 ml / g or less, an ethylene-α-olefin copolymer elastomer (B) and a plasticizer (C), which is a polyamide A polyamide resin composition containing 10 parts by weight to 35 parts by weight of (B) and 1 part to 20 parts by weight of (C) per 100 parts by weight of 610 resin (A).
(2) The polyamide resin composition according to (1), wherein the (B) is a maleic anhydride-modified ethylene-1-butene copolymer.
(3) The polyamide resin composition according to (1) or (2), which has a bar flow flow length of 75 mm or more as determined by a bar flow flow length test according to the following method.
Bar flow flow length test: using a cavity having a thickness of 1 mm and a width of 10 mm, a mold temperature of 40 ° C., a melting point of polyamide resin + a cylinder temperature of 25 ° C., an injection pressure of 30 MPa, an injection speed of 100 mm / s, a screw rotation speed of 100 rpm, and weighing. Measure the bar flow length at a position of 50 mm, suck back 3 mm, injection time 15 s, cooling time 15 s.
(4) A molded article containing the polyamide resin composition according to any one of (1) to (3).
(5) A molded product having a thickness of 1 mm or less, containing the polyamide resin composition according to any one of (1) to (3).

  According to the present invention, it is possible to obtain a polyamide resin composition having excellent elastic modulus retention before and after water absorption, as well as excellent impact resistance, toughness and thin-wall moldability. Generally, a thin-walled molded article has a large change in elastic modulus due to water absorption under use environment, but according to the polyamide resin composition of the present invention, even if it is a thin-walled molded article, it suppresses a decrease in elastic modulus due to water absorption. Therefore, the shape of the molded product can be maintained and the deformation resistance can be excellent. Further, the polyamide resin composition of the present invention is characterized by being excellent in rigidity and impact resistance in spite of being a thin molded product. In addition, the polyamide resin composition of the present invention is excellent in thin-wall moldability, and thus is suitable for a thin-wall molded product having a thickness of 1 mm or less, and even such a thin-wall molded product is excellent in toughness.

The polyamide resin composition of the present invention contains a polyamide 610 resin (A), an ethylene-α-olefin copolymer elastomer (B), and a plasticizer (C).
The polyamide 610 resin used in the present invention is a polyamide resin having hexamethylenediamine as a diamine, sebacic acid as a dicanrubonic acid as a polymerizing monomer, and having a unit composed of hexamethylenediamine and sebacic acid. By using the polyamide 610 resin, the rigidity retention rate before and after water absorption of the molded product, impact resistance, toughness and thin-wall moldability are improved.

The terminal amino group concentration of the polyamide 610 resin (A) used in the present invention is not particularly limited, but the terminal amino group concentration of 2.0 × 10 ⁻⁵ mol / g or more is an ethylene-α-olefin type. The copolymer elastomer (B) is easy to react with, and is preferably 8.0 × 10 ⁻⁵ mol / g or less. The terminal amino group concentration here can be measured by dissolving a polyamide resin in an 85% phenol-ethanol solution, using thymol blue as an indicator, and titrating with an aqueous hydrochloric acid solution.

Although the terminal carboxyl group concentration of the polyamide 610 resin (A) used in the present invention is not limited, the terminal carboxyl group concentration is 2.0 × 10 ⁻⁵ mol / g or more, 15.0 × 10 ⁻⁵ mol / g. The following are preferred because they are excellent in hydrolysis resistance. The term “terminal carboxyl group concentration” as used herein can be measured by heating and dissolving in benzyl alcohol, using a PP indicator, and titrating with an aqueous potassium hydroxide solution having a normality of 0.02N.

  The viscosity number (VN) of the polyamide 610 resin (A) is 135 ml / g or less. If it exceeds 135 ml / g, the viscosity will be high, and the thin article with a thickness of 1 mm or less will have poor fluidity, and the molded article will be insufficiently filled. When the viscosity number (VN) exceeds 135 ml / g, the ethylene-α-olefin copolymer elastomer (B) is stretched at the time of molding to form a layered shape, which is inferior in high-speed tensile elongation at break. When the viscosity number (VN) is 135 ml / g or less, the ethylene-α-olefin copolymer elastomer (B) can maintain a spherical shape, and thus has excellent high-speed tensile elongation at break.

  The viscosity number (VN) is preferably 120 ml / g or less in order to improve the rigidity of the molded product, the rigidity retention before and after water absorption, impact resistance, thin 1 mm high-speed tensile elongation at break, and thin moldability. The most preferable viscosity number (VN) is 110 ml / g or less. The lower limit is not particularly limited, but it is preferably 90 ml / g or more, more preferably 100 ml / g or more, because the toughness is improved. The viscosity number (VN) can be measured according to ISO307.

  The viscosity number (VN) of the polyamide resin contained in the polyamide resin composition is the same as the viscosity number (VN) of the polyamide resin blended as a raw material. Therefore, in the present invention, the viscosity number (VN) of the polyamide resin contained in the polyamide resin composition is the viscosity number (VN) of the polyamide resin used as a raw material. The melting point of the polyamide 610 resin (A) is preferably 215 ° C to 230 ° C.

  The polyamide 610 resin (A) may contain a diamine other than the hexamethylene diamine as a polymerized monomer as long as the object of the embodiment of the present invention is not impaired. As typical examples thereof, amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and para-aminomethylbenzoic acid, lactams such as ε-caprolactam and ω-laurolactam, tetramethylenediamine, pentamethylenediamine, 2-methylpentamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, etc. Aromatic diamines such as aliphatic diamine, metaxylylenediamine, and paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl- 3, 5, 5 -Trimethylcyclohexane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine, etc. Alicyclic diamines and the like.

  Further, the polyamide 610 resin (A) may contain a dicarboxylic acid other than the above sebacic acid as a polymerized monomer within the range that does not impair the object of the embodiment of the present invention. As typical examples thereof, aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid and dodecanedioic acid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5- Aromatic dicarboxylic acids such as sodium sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, hexahydroterephthalic acid and hexahydroisophthalic acid, alicyclic dicarboxylic acids such as 1,2-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid Acid etc. are mentioned. In the present invention, two or more polyamide homopolymers or copolymers derived from these raw materials may be used in combination.

  The method for producing the polyamide 610 resin (A) used in the present invention is not particularly limited as long as it is produced by a known production method. For example, hexamethylenediamine, sebacic acid, (diamines other than hexamethylenediamine, each polymerized monomer such as dicarboxylic acid other than sebacic acid, etc., if necessary), solvent or water, catalyst, polymerization adjusting component, etc. are melted A method of heating and polymerizing, a solid-state polymerization method of increasing the degree of polymerization of a prepolymer that is partially heat-polymerized by heating at a temperature below the melting point in a solid state, and an extrusion weight for increasing the degree of polymerization by melting the prepolymer through an extruder. Legal etc. are mentioned. These polymerization methods may be a batch production method or a continuous production method.

  The polyamide resin composition of the present invention contains an ethylene-α olefin copolymer elastomer (B). The ethylene-α-olefin copolymer elastomer (B) of the present invention generally contains a polymer having a glass transition temperature lower than room temperature, and a part of the molecules has covalent bonds, ionic bonds, van der Waals forces, It refers to a copolymer of an ethylene monomer and an α-olefin-based polymer, which is constrained by entanglement or the like. For example, α-olefin-based polymer means polybutadiene, polyisoprene, random copolymer and block copolymer of styrene-butadiene, hydrogenated product of the block copolymer, acrylonitrile-butadiene copolymer, butadiene-isoprene copolymer. Examples thereof include diene rubbers such as polymers, ethylene-unsaturated carboxylic acid ester copolymers, ethylene, propylene, 1-butene, 1-pentene and 1-octene.

  Among these ethylene-α olefin-based copolymer elastomers (B), from the viewpoint of improving the impact resistance of a molded product obtained by molding a polyamide resin composition, an ethylene-propylene copolymer and an ethylene-1-butene copolymer are used. A polymer, an ethylene-1-octene copolymer, and a propylene-1-butene copolymer are preferable, and an ethylene-1-butene copolymer and an ethylene-1-octene copolymer are particularly preferable.

  The ethylene-α olefin copolymer elastomer (B) used in the present invention may have a reactive functional group. Specific examples of the reactive functional group include at least one reactive functional group selected from the group consisting of an acid anhydride group, an epoxy group, an amino group, a carboxyl group, a carboxyl metal salt and an oxazoline group. In particular, an epoxy group, an acid anhydride group, and a carboxyl group are preferably used because they have high reactivity with a polyamide resin and have little side reaction such as decomposition and crosslinking of themselves.

  Examples of the functional group-containing component for introducing an acid anhydride group include maleic anhydride, itaconic anhydride, citraconic anhydride, 1-butene-3,4-dicarboxylic acid anhydride, and the like. Among them, maleic anhydride and itaconic anhydride are preferably used. These may be used alone or in combination of two or more.

  As a functional group-containing component for introducing an epoxy group, a vinyl-based compound having an epoxy group such as glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylic acid, glycidyl itaconate, and the like, a glycidyl ester compound of an α, β-unsaturated acid. Monomers are preferably used.

  Further, a carboxyl metal salt in which a part of the carboxyl group is a metal salt is also effective as a functional group-containing component for introducing a carboxyl group, and examples thereof include (meth) acrylic acid metal salt. The metal of the metal salt is not particularly limited, but preferably, an alkali metal such as sodium, an alkaline earth metal such as magnesium, zinc and the like can be mentioned.

  As a functional group-containing component for introducing an oxazoline group, a vinyl monomer having an oxazoline group such as 2-isopropenyl-oxazoline, 2-vinyl-oxazoline, 2-acryloyl-oxazoline, and 2-styryl-oxazoline is used. It is preferably used.

  When the functional group is introduced into the ethylene-α-olefin copolymer elastomer, the method can be carried out by a generally known technique and is not particularly limited.

  The number of functional groups per one molecular chain in the ethylene-α-olefin-based copolymer elastomer having a reactive functional group is not particularly limited, but it is usually preferably 1 to 10 to reduce side reactions such as crosslinking. Therefore, 1 to 5 is more preferable. Further, a molecule having no functional group may be contained, but the smaller the ratio, the better.

  In the present invention, the ethylene-α-olefin copolymer elastomer having a reactive functional group includes a maleic anhydride modified ethylene-propylene copolymer, a maleic anhydride modified ethylene-1-butene copolymer, and a maleic anhydride modified ethylene. -1-Octene copolymer, maleic anhydride-modified propylene-1-butene copolymer are preferable, and maleic anhydride-modified ethylene-1-butene copolymer and maleic anhydride-modified ethylene-1-octene copolymer are particularly preferable. preferable.

  The polyamide resin composition of the present invention contains 10 parts by weight or more and 35 parts by weight or less of the ethylene-α-olefin copolymer elastomer (B) with respect to 100 parts by weight of the polyamide 610 resin (A).

  When the amount of the ethylene-α-olefin-based copolymer elastomer (B) used in the present invention is less than 10 parts by weight, the elastic modulus is high because the content of the polyamide resin is relatively large, and the impact resistance of the molded product is high. Inferior. Further, when the ethylene-α-olefin copolymer elastomer (B) is less than 10 parts by weight, the amount of polyamide 610 resin (A) increases, so that the strength of the molded product decreases when absorbing water, and in the case of a thin molded product, It becomes significantly more susceptible to water absorption. That is, the strength retention before and after water absorption decreases.

  On the other hand, when the ethylene-α-olefin-based copolymer elastomer (B) used in the present invention exceeds 35 parts by weight, the content of the polyamide resin becomes relatively small, so that the elastic modulus becomes low and the rigidity of the molded product becomes low. Inferior. Further, when the amount of the ethylene-α-olefin-based copolymer elastomer (B) exceeds 35 parts by weight, the content of the polyamide 610 resin (A) is relatively reduced, which may make it difficult to perform thin-wall molding. A more preferable range of the ethylene-α-olefin copolymer elastomer (B) is 11 parts by weight or more and 30 parts by weight or less.

  The polyamide resin composition of the present invention further contains a plasticizer (C) in addition to the polyamide resin 610 (A) and the ethylene-α-olefin copolymer elastomer (B).

  The plasticizer (C) used in the present invention has a role of softening the amorphous part of the polyamide resin 610 (A) and softening the polyamide resin in an absolutely dry state. Although the mechanism of softening is not clear, in the polyamide resin composition of the present invention, the plasticizer present between the polyamide resin molecules having a specific viscosity number spreads the molecules and improves the mobility of the polyamide resin molecules. . That is, it is presumed that the softening of the polyamide resin can be achieved by lowering the glass transition temperature.

  There is no particular limitation as long as it is a plasticizer applicable to the polyamide resin, but an amide plasticizer, an ester plasticizer, or an amide ester plasticizer can be used. Examples of the amide plasticizer include carboxylic acid amide plasticizers and sulfonamide plasticizers. Examples of the carboxylic acid amide-based plasticizer include one or more kinds of acids selected from the group consisting of benzoic acid, phthalic acid, trimellitic acid, pyromellitic acid and their anhydrides, and an alkyl group having 2 to 8 carbon atoms. Examples include amides with dialkylamines. Examples of the dialkylamine having an alkyl group having 2 to 8 carbon atoms include diethylamine, dipropylamine, dibutylamine, dihexylamine, di2-ethylhexylamine and dioctylamine. The plasticizers preferably used in the present invention are sulfonamide type plasticizers, examples of which include sulfonamides including N-alkylbenzene sulfonamides and toluene sulfonamides. Suitable examples are N-butylbenzenesulfonamide, N- (2-hydroxypropyl) benzenesulfonamide, N-ethyl-o-toluenesulfonamide, N-ethyl-p-toluenesulfonamide, o-toluenesulfonamide. , P-toluenesulfonamide. Most preferably, N-butylbenzenesulfonamide is used.

  The polyamide resin composition of the present invention contains the plasticizer (C) in an amount of 1 part by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the polyamide 610 resin (A). When the amount of the plasticizer (C) used in the present invention is less than 1 part by weight, the amount of the polyamide 610 resin (A) increases, the elastic modulus of the polyamide resin increases, and the impact resistance of the molded product deteriorates. On the other hand, when the amount of the plasticizer (C) used in the present invention exceeds 20 parts by weight, the content of the polyamide 610 resin (A) is relatively small, the elastic modulus of the polyamide resin is low, and the rigidity of the molded product is low. And inferior in rigidity retention rate. The preferred range of the plasticizer (C) is 5 parts by weight or more and 15 parts by weight or less.

  As described above, the polyamide resin composition of the present invention contains the polyamide 610 resin (A), the ethylene-α-olefin copolymer elastomer (B), and the plasticizer (C) in specific amounts. A thin-walled molded article absorbs water more easily than a thick-walled molded article, and the water absorption directly affects mechanical properties. As a result of investigating how to suppress the water absorption of a molded product having a thin shape, the inventors of the present invention have found that a polyamide 610 resin (A), an ethylene-α-olefin-based copolymer elastomer (B) and a plasticizer (C It has been found that the inclusion of) lowers the elastic modulus of the molded product at the time of absolute drying, so that the elastic modulus before and after water absorption does not easily change. In addition, they have found that the fluidity is also improved. As described above, according to the present invention, a polyamide resin composition that achieves a decrease in elastic modulus during absolute drying, has an excellent elastic modulus retention rate before and after water absorption, and can be used in a thin molded product having a thickness of 1 mm or less is characterized by good flowability. You can get things.

  The polyamide resin composition of the present invention preferably contains a crystal nucleating agent (D). Since the crystallinity can be increased by adding the crystal nucleating agent, the rigidity of the polyamide resin composition can be improved. Further, the crystallization temperature becomes high, the solidification can be accelerated during the injection molding, and the molding time can be shortened, so that the thin wall moldability can be improved. Types of crystal nucleating agents include talc, wollastonite, calcite, aragonite, dolomite, kaolin, mica, titanium oxide, carbon black and other inorganic nucleating agents, benzotriazole-based, phenol-based, phosphorus-based, etc. Examples of the organic nucleating agent include organic nucleating agents such as metal salts of group carboxylic acids, sorbitol derivatives, organic phosphates and aromatic amide compounds. From the viewpoint of improving the rigidity of the polyamide resin and accelerating the solidification, talc is preferable.

  Commercially available products of talc include “Micron White” (registered trademark) # 7000, “Micron White” (registered trademark) # 5000A, “Micron White” (registered trademark) # 5000, “Talc” (registered trademark) MST (above). , Hayashi Kasei Co., Ltd., Talc FH104A, Talc PK-C (above, Fuji Talc Industry Co., Ltd.) and the like.

  The crystal nucleating agent (D) is preferably contained in 0.005 or more and 5.0 parts by weight or less with respect to 100 parts by weight of the polyamide 610 resin (A).

  The polyamide resin composition of the present invention preferably contains a release agent (E). By adding the mold release agent, the mold release resistance when the polyamide resin composition is released from the mold during injection molding becomes small, and the moldability is excellent. The mold releasability can be improved even in a thin-walled molded product or a molded product having a complicated shape. The mechanism of improving the mold releasability is that the mold releasing agent melts at the mold surface temperature and improves the slipperiness between the molded product and the mold. The type of the release agent is preferably at least one selected from fatty acid amides, fatty acid esters, fatty acid metal salts, oxyfatty acids, partially saponified fatty acid esters, paraffins, low molecular weight polyolefins, and alkylenebisfatty acid amides. Fatty acid esters are preferred.

  As the fatty acid ester, stearic acid ester, oleic acid ester, linoleic acid ester, linolenic acid ester, adipic acid ester, behenic acid ester, arachidic acid ester, montanic acid ester, isostearic acid ester, ester of polymeric acid, and aliphatic moiety Examples of the saponified ester include a partially saponified ester of montanic acid. Of the above, montanic acid ester and partially saponified montanic acid ester can be preferably used, and among them, partially saponified montanic acid ester is most preferable. In the present invention, the fatty acid ester may be used alone or in combination of two or more.

  The release agent (E) is preferably contained in an amount of 0.01 to 5.0 parts by weight based on 100 parts by weight of the polyamide 610 resin (A). If it is less than 0.01 part by weight, the molded product may be deformed or chipped at the time of mold release in injection molding, and if it exceeds 5.0 parts by weight, stains are formed on the surface of the mold at the time of molding. From poor transfer to poor appearance of molded products. Further, when an external force acts such as post-processing or assembling after molding, cracks may occur at the time of assembling the product, starting from flow marks or wrinkles formed on the surface of the molded product. The flowability (thin-wall moldability) of the polyamide resin composition of the present invention can be evaluated by a bar flow flow length test using a cavity having a thickness of 1 mm and a width of 10 mm. The molding conditions are a mold temperature of 40 ° C., a polyamide resin melting point of + 25 ° C., and a cylinder temperature of 25 ° C., and the length in the flow direction of a bar flow molded product when molded at an injection pressure of 30 MPa can be measured. The bar flow flow length is preferably 75 mm or more, and when it is less than 75 mm, the thin-wall flowability is poor. When the thin-wall fluidity is inferior, the molded product is affected by strain, so that the high-speed tensile elongation at break is inferior. Although the upper limit is not particularly limited, when the bar flow flow length is 150 mm or more, the flowability is excellent, but burrs are generated at the end of the molded product, resulting in poor appearance. A particularly preferable range of the bar flow flow length is 78 mm or more and less than 150 mm.

  The method for producing the polyamide resin composition of the present invention is not particularly limited. Polyamide 610 resin (A), ethylene-α-olefin copolymer elastomer (B), plasticizer (C) and, if necessary, crystal nucleating agent (D) and release agent (E) are blended together and melted. In the method of kneading, polyamide 610 resin (A), ethylene-α-olefin copolymer elastomer (B), and optionally a crystal nucleating agent (D) and a releasing agent (E) are melted and kneaded. Examples include a method of adding the agent (C) by a method such as side feeding.

  The polyamide resin composition used in the present invention may contain other thermoplastic resin, if necessary, as long as the characteristics thereof are not impaired.

  For example, other thermoplastic resins include polyamide resins other than polyamide 610 resin (A), polyester resins, polyphenylene sulfide resins, polyphenylene oxide resins, polycarbonate resins, polylactic acid resins, polyacetal resins, polysulfone resins, tetrafluoropolyethylene. Resin, polyetherimide resin, polyamideimide resin, polyimide resin, polyethersulfone resin, polyetherketone resin, polythioetherketone resin, polyetheretherketone resin, polyethylene resin, styrene resin such as polystyrene resin and ABS resin, poly Examples thereof include alkylene oxide resins.

  Examples of polyamide resins other than the above-mentioned polyamide 610 resin (A) include polyamide 6, polyamide 66, polyamide 56, polyamide 510, polyamide 410, polyamide 612, polyamide 11, polyamide 12, polyamide 6/66, polyamide 66 / 6T, polyamide 6T / 6I, polyamide 66 / 6I / 6, polyamide 6T / M5T, polyamide 9T, polyamide 9T / M8T, polyamide 10T and the like. Among polyamide resins other than these polyamide resins (A), polyamide 66, polyamide 612, polyamide 11, polyamide 12, polyamide 6T / M5T, polyamide 9T, polyamide 9T / M8T, from the viewpoint of balance between moldability, rigidity and toughness, Polyamide 10T is more preferred. Particularly preferred polyamide resins are polyamide 11 and polyamide 12. It is also possible to use two or more of these thermoplastic resins in combination.

  When such a thermoplastic resin is used, the content is not limited, but is preferably 0.1 part by weight or more and less than 70 parts by weight with respect to 100 parts by weight of the polyamide 610 resin (A).

  The polyamide resin composition of the present invention is an ordinary UV absorber, a coloring inhibitor, a weathering agent, a lubricant, an antistatic agent, a flame retardant, and a coloring agent containing a dye / pigment, etc. within a range that does not impair the object of the present invention. One or more kinds of additives can be added.

  Examples of such various additives include, for example, resorcinol-based, salicylate-based, benzotriazole-based, benzophenone-based, hindered amine-based weathering agents, octyl p-oxybenzoate, lubricants such as wax, alkyl sulfate-type anion-based, quaternary Ammonium salt type cation type, nonionic type such as polyoxyethylene sorbitan monostearate, betaine type amphoteric antistatic agent, melamine cyanurate, hydroxides of magnesium hydroxide, aluminum hydroxide, ammonium polyphosphate, brominated Polystyrene, brominated polyphenylene oxide, brominated polycarbonate, flame retardants such as brominated epoxy resin or a combination of these brominated flame retardants and antimony trioxide, azo dyes, anthraquinone dyes, perylene dyes, azo dyes, Nsurakinon type, phthalocyanine type, quinacridone, perylene, zinc-based, and a colorant comprising a pigment such as ultramarine.

  Two or more kinds of various additives such as the ultraviolet absorber, the anti-coloring agent, the weather resistance agent, the lubricant, the antistatic agent, the flame retardant, and the colorant including the dye / pigment can be used in combination. The content is not particularly limited, but is preferably 0.01 or more and less than 5 parts by weight with respect to 100 parts by weight of the polyamide 610 resin (A).

  These thermoplastic resins and additives can be blended at any stage of producing the thermoplastic resin composition, and for example, polyamide 610 resin (A), ethylene-α olefin copolymer elastomer ( B), a plasticizer (C), a crystal nucleating agent (D), and a release agent (E) are added at the same time when they are compounded, and melt kneading is performed, or a method such as side feeding during melt kneading is used. Can be mentioned.

  The thermoplastic resin composition of the present invention can be molded by any method. Examples of the molding method include extrusion molding, injection molding, hollow molding, calendar molding, compression molding, vacuum molding, foam molding, blow molding and rotational molding. Examples of the molding shape include a plate shape, a fiber shape, an uneven shape, a strand shape, a film or sheet shape, a pipe shape, a hollow shape, a box shape, and a nail shape.

  The obtained molded product can be applied to various applications such as electric / electronic parts, automobile parts, vehicle parts, building material parts, general / industrial machine parts, sports goods, household goods, household / office supplies, and furniture parts. Above all, it is suitably used for thin-walled molded products such as nets, lattice-shaped molded products, sheets, buttons and electronic device cover parts. More specifically, it is suitably used for a molded product having a thickness of 1 mm or less. The thickness of the molded product in the present invention means the thickness of the thickest part of the molded product. If the molded product has ribs, hinges, bosses, etc., exclude them.

  Examples of the net and the lattice-shaped molded product include those having a lattice-like shape, and specific examples thereof include a net net, a curtain, a draining bowl, a colander, a triangular corner, a resin mesh, and a mesh filter. Specific examples of the button include a snap button and a packing for a dry battery. The electronic device cover component is a casing of any electronic device, and examples thereof include a casing portion of a television, a personal computer, a smartphone, a mobile phone, and the like.

  Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples. First, the evaluation method in each Example and Comparative Example will be described.

(1) Rigidity (flexural modulus)
(1.1) Bending elastic modulus (E ₀ ) when absolutely dried
Using the ISO3167 standard Type-IA multipurpose test piece obtained in each Example and Comparative Example, a bending test was carried out according to ISO178, and the bending elastic modulus (E ₀ ) was measured.
(1.2) Flexural modulus (E) at atmospheric equilibrium water absorption
The ISO3167 standard Type-IA multipurpose test piece obtained in each Example and Comparative Example was stored for 2 weeks in the atmosphere of 23 ° C. and 50% relative humidity. The water absorption of the multipurpose test piece after storage was defined as the atmospheric equilibrium water absorption. A bending test was carried out on the multipurpose test piece in an atmospheric equilibrium water absorption state in accordance with ISO178 to measure the bending elastic modulus (E).
(1.3) The bending elastic modulus described in (1.1) and (1.2) was measured three times, and the average value was taken as the bending elastic modulus.

(2) Rigidity retention rate (E ')
The modulus of elasticity (E ₀ ) at the time of water absorption is subtracted from the modulus of elasticity (E ₀ ) at the time of absolutely dryness, and the percentage is calculated by dividing the modulus of elasticity (E ₀ ) at the time of absolutely dryness. The formula for calculating the rigidity retention rate (E ′) is as shown in the following formula (1).
E ′ = E × 100 / E ₀ Formula (1)
E ': Elastic modulus retention rate before and after water absorption E ₀ : Elastic modulus E in absolutely dry condition : Elastic modulus when absorbing water.

(3) Impact resistance ISO3167 standard Type-IA multipurpose test pieces obtained in each of the examples and comparative examples were injection molded, and a length of 80 mm × width of 10 mm × thickness of 4 mm was measured from a parallel portion of the obtained test pieces. A Charpy impact test piece (with a notch) was cut out. Using this Charpy impact test piece, the Charpy impact strength (with a notch) was measured according to ISO179. The Charpy impact strength (with notch) was performed 7 times, and the average value was defined as the Charpy impact strength (with notch).

(4) Toughness (thin wall 1 mm high-speed tensile elongation at break)
Using ASTM No. 4 dumbbell-shaped test pieces obtained in the respective examples and comparative examples, a tensile test was carried out at a tensile speed of 100 mm / min in accordance with ASTM D638, and the tensile elongation at break was measured.

(5) Thin-wall moldability The polyamide resin composition pellets obtained in each of the examples and comparative examples are vacuum-dried under the conditions of 40 ° C. and 24 hours, and subjected to the following injection molding conditions, and the bar-flow molding having a thickness of 1 mm and a width of 10 mm A product was prepared and the bar flow length was measured. The injection conditions are as follows: mold temperature 40 ° C., injection pressure 30 MPa, injection speed 100 mm / s, screw rotation speed 100 rpm, metering position 50 mm, suck back 3 mm, injection time 15 s, cooling time at cylinder temperature of polyamide resin melting point + 25 ° C. 15s. The bar flow flow length was measured 10 times, and the average value was used as the bar flow flow length.

(6) Solidification characteristics The polyamide resin composition pellets obtained in each Example and Comparative Example were vacuum dried under the conditions of 40 ° C and 24 hours, and the melting point (Tm) and the crystallization temperature (Tc) were measured by DSC. Tm-Tc was evaluated as an index of crystallization characteristics.

(7) Releasability The polyamide resin composition pellets obtained in each of the examples and comparative examples were vacuum dried under the conditions of 40 ° C. and 24 hours, and were subjected to the following injection molding conditions: 25 mm × 25 mm × 25 mm, wall thickness: 1 mm A box-shaped molded article was prepared. The load applied to the ejector plate during mold release was measured with a load cell, and this value was used as the mold release force. The injection conditions are as follows: mold temperature 40 ° C., injection pressure 100 MPa, injection speed 100 mm / s, screw rotation speed 100 rpm, metering position 50 mm, suck back 3 mm, injection time 15 s, cooling time at cylinder temperature of polyamide resin melting point + 25 ° C. 15s.

  The raw materials used in each Example and Comparative Example are shown below.

Polyamide resin:
A-1: Polyamide 610 resin having a melting point of 225 ° C. and a viscosity number measured according to ISO307 of 109 ml / g.
A-2: Polyamide 610 resin having a melting point of 225 ° C. and a viscosity number of 132 ml / g measured according to ISO307.
A-3: Polyamide 610 resin having a melting point of 225 ° C. and a viscosity number measured according to ISO307 of 140 ml / g.
A-4: Polyamide 6 resin having a melting point of 225 ° C. and a viscosity number of 132 ml / g measured according to ISO307.
A-5: Polyamide 12 resin having a melting point of 185 ° C. and a viscosity number of 132 ml / g measured according to ISO307.

Ethylene-α olefin copolymer elastomer (B)
B-1: Maleic anhydride-modified ethylene-1-butene copolymer ““ Toughmer ”(registered trademark) MH7020” (manufactured by Mitsui Chemicals, Inc.).
B-2: Ethylene-propylene-diene rubber (EPDM) (produced by Prime Polymer Co., Ltd.).

Plasticizer (C)
C-1: N-butylbenzenesulfonamide "BBSA" (manufactured by Toray Fine Chemical Co., Ltd.).

Crystal nucleating agent (D)
D-1: “Micron White” (registered trademark) # 7000 (manufactured by Hayashi Kasei Co., Ltd.).
D-2: Titanium oxide A-220 (manufactured by Ishihara Sangyo Co., Ltd.).

Release agent (E)
E-1: Licowax OP (Montanic acid partially saponified ester wax) (manufactured by Clariant Chemicals Co., Ltd.)

(Examples 1 to 10, Comparative Examples 1 to 8)
Mixing with the composition shown in Tables 1 to 3 and using a vacuum pump to remove volatile components, a twin screw extruder with a screw diameter of 75 mm (manufactured by Toshiba Machine Co., TEM75) was used, and the barrel set temperature was 240 to 270. Melt extruded at ° C. The discharge rate was 70 kg / hr and the screw rotation speed was 300 rpm. A pellet of the polyamide resin composition was obtained by pulling the discharged resin in a strand shape, allowing it to pass through a cooling bath to cool, and cutting while taking it with a pelletizer. The pellets of the obtained polyamide resin composition were vacuum dried under the conditions of 40 ° C. and 24 hours, and using a NEX1000 molding machine manufactured by Nissei Plastic Industry Co., Ltd., at a cylinder temperature of the melting point of polyamide resin + 25 ° C., a mold temperature of 40 ° C. By injection molding under conditions of an injection speed of 100 mm / s and a screw rotation speed of 100 rpm, an ISO3167 standard Type-IA multipurpose test piece (length 170 mm, parallel portion width 10 mm, thickness 4 mm) was obtained. Bending elastic modulus, impact resistance, thin-wall 1 mm tensile elongation at break and thin-wall formability were measured using the obtained multipurpose test piece. The results evaluated by the above method are shown in Tables 1 to 3.

  Examples 1 to 10 are superior to Comparative Examples 1 to 8 in the rigidity retention of molded products, impact resistance, and thin-wall moldability. Since Example 1 contains the polyamide 610 resin (A) having a viscosity number (VN) more preferable than that of Example 6, it is more excellent in fluidity.

Claims (5)

A polyamide resin composition containing a polyamide 610 resin (A) having a viscosity number (VN) of 135 ml / g or less, an ethylene-α-olefin copolymer elastomer (B) and a plasticizer (C), which comprises a polyamide 610 resin ( A) A polyamide resin composition containing 10 parts by weight or more and 35 parts by weight or less, and 1 part by weight or more and 20 parts by weight or less of (C) with respect to 100 parts by weight of A). The polyamide resin composition according to claim 1, wherein the (B) is a maleic anhydride-modified ethylene-1-butene copolymer. The polyamide resin composition according to claim 1 or 2, which has a bar flow flow length of 75 mm or more as determined by a bar flow flow length test according to the following method.
Bar flow flow length test: using a cavity having a thickness of 1 mm and a width of 10 mm, a mold temperature of 40 ° C., a melting point of polyamide resin + a cylinder temperature of 25 ° C., an injection pressure of 30 MPa, an injection speed of 100 mm / s, a screw rotation speed of 100 rpm, and weighing. Measure the bar flow length at a position of 50 mm, suck back 3 mm, injection time 15 s, cooling time 15 s. A molded article containing the polyamide resin composition according to claim 1. A molded product having a thickness of 1 mm or less, containing the polyamide resin composition according to claim 1.